lake Toplitz

Take a stroll along the secluded banks of Lake Toplitz in Austria, near what was once Hitler's propaganda chief Joseph Goebbels' sumptuous summer villa, and you will sometimes see men diving into the cold, inky water or prodding around near to the shore, with long sticks and metal detectors.

It is a dangerous business - 25 divers have lost their lives in the lake's 426 feet depths. Occasionally over the past 50 years, someone has struck lucky and retrieved a rusty box or some fragments of paper.

However, these are not casual enthusiasts - they are seeking the Nazis' biggest treasure trove.

In metal boxes marked ' munitions' are the results of the biggest counterfeit operation in history; nearly £1billion of forged British banknotes which the nazis planned to drop into Britain to create massive inflation and destroy the economy.

Now I am preparing to dive into the lake myself. With me is a young man called Franz, who looks like Sacha Baron Cohen's character Bruno dressed in his short, tight lederhosen.

The area, 60 miles from the city of Salzburg, is the congregating ground for Austria's neo-Nazis.